Iraqi forces have reached the southern outskirts of Mosul on the second day of a new push to drive Islamic State militants from the western half of the city.
Iraqi helicopters were seen firing rockets at the village of Abu Saif, mainly at a hill that overlooks the city's airport and provides the militants with a natural defence line on the southern approaches to Mosul.
Separately, police forces in armoured vehicles were moving towards the sprawling Ghazlani military base on the south-western outskirts of the city.
Backed by aerial support from the US-led international coalition, Iraqi police and regular army troops launched an offensive on Sunday to retake western Mosul from IS following a 100-day campaign that pushed the militants from the eastern half of the city.
The push came as US defence secretary Jim Mattis started a visit to Iraq to discuss the fight against IS.
On Sunday, while in the United Arab Emirates capital Abu Dhabi, Mr Mattis said that US troops "are very close to it, if not already engaged in that fight".
Mr Mattis declined to go into further detail, saying he owed "confidentiality" to the troops.
Under US president Donald Trump's deadline, Mr Mattis has just a week to prepare a strategy to accelerate the fight and defeat IS. Any plan is likely to depend on US and coalition troops working with and through the local forces in both Iraq and Syria.
"We're going to make certain that we've got good situational awareness of what we face as we work together and fight alongside each other," Mr Mattis said.
His key goal during the visit to Baghdad is to discuss the military operations with political leaders and commanders on the ground, including his top commander in Iraq, Lt Gen Stephen Townsend.
The US-led coalition has been providing close air support throughout the four-month Mosul offensive, while US special operations forces are embedded with some Iraqi units and thousands of American soldiers are in Iraq to provide logistical and other support.
There are more than 5,100 US forces in Iraq, and about 500 in Syria.
Mosul, Iraq's second largest city and the last IS urban stronghold in the country, fell into the hands of the extremists in the summer of 2014, when the group captured large areas of northern and western Iraq.
